50278 + Interview Questions in Physics

1.	The value of ∫dx1+3cos2x(where C is integration constant)
Answer» The value of $\int \frac{d x}{1 + 3 {cos}^{2} x}$ (where $C$ is integration constant)

Discussion

2.	Three particles, each of mass m, are placed at the corners of a right-angled triangle as shown in the figure. If OA = a and OB = b, the position vector of the centre of mass is
Answer» Three particles, each of mass m, are placed at the corners of a right-angled triangle as shown in the figure. If OA = a and OB = b, the position vector of the centre of mass is

Discussion

3.	particle A makes a perfectly elastic collision with another particle B at rest. they fly apart in opposite direction with equal speeds. If their masses are mA and mB respectively, then (a)2ma=mB (b)3mA=mB (c)4mA=mB (d)\surd3mA= m
Answer» particle A makes a perfectly elastic collision with another particle B at rest. they fly apart in opposite direction with equal speeds. If their masses are mA and mB respectively, then (a)2ma=mB (b)3mA=mB (c)4mA=mB (d)\surd3mA= m

Discussion

4.	Give the expansions of PSLV and GSLV.
Answer» Give the expansions of PSLV and GSLV.

Discussion

5.	The diagram shows a cyclic process performed on one mole of an ideal gas. A total of 1000 J of heat is withdrawn from the gas in a complete cycle. Find the work done by the gas in the process B→C
Answer» The diagram shows a cyclic process performed on one mole of an ideal gas. A total of $1000 J$ of heat is withdrawn from the gas in a complete cycle. Find the work done by the gas in the process $B \to C$

Discussion

6.	Electric field close to plane of charge is shown in figure. External electric field in V/m is
Answer» Electric field close to plane of charge is shown in figure. External electric field in V/m is

Discussion

7.	In a wire of cross-section radius r, free electrons travel with drift velocity vd, when a current I flows through the wire. What is the current in another wire of half the radius and of the same material, when the drift velocity is 2vd ?
Answer» In a wire of cross-section radius $r$ , free electrons travel with drift velocity $v_{d},$ when a current $I$ flows through the wire. What is the current in another wire of half the radius and of the same material, when the drift velocity is $2 v_{d}$ ?

Discussion

8.	A satellite of mass m is launched vertically upward with an initial speed u from the surface of the earth. After it reaches height R (R = radius of earth), it ejects a rocket of mass m/10 so that subsequently the satellite moves in a circular orbit. The kinetic energy of the rocket is (G = gravitational constant; M is the mass of earth)
Answer» A satellite of mass $m$ is launched vertically upward with an initial speed $u$ from the surface of the earth. After it reaches height $R$ ( $R$ = radius of earth), it ejects a rocket of mass $m / 10$ so that subsequently the satellite moves in a circular orbit. The kinetic energy of the rocket is (G = gravitational constant; M is the mass of earth)

Discussion

9.	20.Calculate the acceleration of the masses 12kg shown in figure. Also calculate the tension in the string connecting the 12kg mass the string are massless and unextensible. Pulleys are massless and frictionless
Answer» 20.Calculate the acceleration of the masses 12kg shown in figure. Also calculate the tension in the string connecting the 12kg mass the string are massless and unextensible. Pulleys are massless and frictionless

Discussion

10.	What should be the value of the refractive index n of a glass rod placed in air so that the light entering through flat surface of the rod does not cross the curved surface of the rod?
Answer» What should be the value of the refractive index $n$ of a glass rod placed in air so that the light entering through flat surface of the rod does not cross the curved surface of the rod?

Discussion

11.	11. if there are 3 electrons present in each orbital and bohr -burry principal is not followed in filling of electrons the number of elements in 4th period of modern periodic table will be:
Answer» 11. if there are 3 electrons present in each orbital and bohr -burry principal is not followed in filling of electrons the number of elements in 4th period of modern periodic table will be:

Discussion

12.	A solid cylinder of height h and cross sectional area a and density 1.40 multiply 1000 kilogram permetre cube is immersed completely in a mixture of liquid such that it floats with its Axis vertical are the liquid liquid interface with length 3 h/4 intense liquid that is less than other as shown in the figure the lesser than solid liquid is opened atmospheric pressure p. if the density of lesser denser liquid is 1000 kilogram per metre cube then the density of denser liquid will be
Answer» A solid cylinder of height h and cross sectional area a and density 1.40 multiply 1000 kilogram permetre cube is immersed completely in a mixture of liquid such that it floats with its Axis vertical are the liquid liquid interface with length 3 h/4 intense liquid that is less than other as shown in the figure the lesser than solid liquid is opened atmospheric pressure p. if the density of lesser denser liquid is 1000 kilogram per metre cube then the density of denser liquid will be

Discussion

13.	A horizontal straight wire 10 m long extending from east to west isfalling with a speed of 5.0 m s–1, at right angles to the horizontalcomponent of the earth’s magnetic field, 0.30 × 10–4 Wb m–2. (a) What is the instantaneous value of the emf induced in the wire? (b) What is the direction of the emf? (c) Which end of the wire is at the higher electrical potential?
Answer» A horizontal straight wire 10 m long extending from east to west isfalling with a speed of 5.0 m s–1, at right angles to the horizontalcomponent of the earth’s magnetic field, 0.30 × 10–4 Wb m–2. (a) What is the instantaneous value of the emf induced in the wire? (b) What is the direction of the emf? (c) Which end of the wire is at the higher electrical potential?

Discussion

14.	A pair of spur gears with module 5 mm and a center distance of 450 mm is used for a speed reduction of 5 : 1. The number of teeth on pinion is
Answer» A pair of spur gears with module 5 mm and a center distance of 450 mm is used for a speed reduction of 5 : 1. The number of teeth on pinion is

Discussion

15.	An electron emitted by a heated cathode and accelerated through apotential difference of 2.0 kV, enters a region with uniform magneticfield of 0.15 T. Determine the trajectory of the electron if the field (a) is transverse to its initial velocity, (b) makes an angle of 30º withthe initial velocity.
Answer» An electron emitted by a heated cathode and accelerated through apotential difference of 2.0 kV, enters a region with uniform magneticfield of 0.15 T. Determine the trajectory of the electron if the field (a) is transverse to its initial velocity, (b) makes an angle of 30º withthe initial velocity.

Discussion

16.	Two heavy spheres each of mass 100 kg and radius 0.10 m are placed 1.0 m apart on a horizontal table. What is the gravitational force and potential at the mid point of the line joining the centres of the spheres ? Is an object placed at that point in equilibrium? If so, is the equilibrium stable or unstable ?
Answer» Two heavy spheres each of mass 100 kg and radius 0.10 m are placed 1.0 m apart on a horizontal table. What is the gravitational force and potential at the mid point of the line joining the centres of the spheres ? Is an object placed at that point in equilibrium? If so, is the equilibrium stable or unstable ?

Discussion

17.	A car of mass 1000 kg moves on a circular track of radius 20 m, if the coefficient of friction is 0.64 then the maximum velocity with which the car can move is
Answer» A car of mass 1000 kg moves on a circular track of radius 20 m, if the coefficient of friction is 0.64 then the maximum velocity with which the car can move is

Discussion

18.	A policeman moving on a highway with a speed of 30 kmh−1 fires a bullet at a thief's car speeding away in the same direction with a speed of 192 kmh−1. If the muzzle speed of the bullet is 150 ms−1 with what speed does the bullet hit the thief's car?
Answer» A policeman moving on a highway with a speed of $30 {kmh}^{- 1}$ fires a bullet at a thief's car speeding away in the same direction with a speed of $192 {kmh}^{- 1}$ . If the muzzle speed of the bullet is $150 {ms}^{- 1}$ with what speed does the bullet hit the thief's car?

Discussion

19.	78. With increase in frequency of an AC supply, the impedance of an LCR circuit a) remain constant b) increases c) decreases d) decrease at first, becomes minimum and then increases
Answer» 78. With increase in frequency of an AC supply, the impedance of an LCR circuit a) remain constant b) increases c) decreases d) decrease at first, becomes minimum and then increases

Discussion

20.	A particle travels along the arc of a circle of radius r.Its speed depends on the distance travelled L as v=aL,where 'a'is a constant. The angle a between the vectors of total acceleration and the velocity of the particle is
Answer» A particle travels along the arc of a circle of radius r.Its speed depends on the distance travelled L as v=aL,where 'a'is a constant. The angle a between the vectors of total acceleration and the velocity of the particle is

Discussion

21.	A uniform square wooden sheet of side a has its centre of mass located at point O as shown in the figure on the left. A square portion of side b of this sheet is cut out to produce and L- Shaped sheet as shown in the figure on the rightThe centre of mass of the L-shaped sheet lies at the point P (in the diagram) when
Answer» A uniform square wooden sheet of side a has its centre of mass located at point O as shown in the figure on the left. A square portion of side b of this sheet is cut out to produce and L- Shaped sheet as shown in the figure on the right The centre of mass of the L-shaped sheet lies at the point P (in the diagram) when

21.

A uniform square wooden sheet of side a has its centre of mass located at point O as shown in the figure on the left. A square portion of side b of this sheet is cut out to produce and L- Shaped sheet as shown in the figure on the rightThe centre of mass of the L-shaped sheet lies at the point P (in the diagram) when

Answer»

A uniform square wooden sheet of side a has its centre of mass located at point O as shown in the figure on the left. A square portion of side b of this sheet is cut out to produce and L- Shaped sheet as shown in the figure on the right

The centre of mass of the L-shaped sheet lies at the point P (in the diagram) when

Discussion

22.	A projectile is thrown with speed 40 m/s at angle theta from horizontal.It is found that projectile is at same height at 1s and 3s.What is the angle of projection?
Answer» A projectile is thrown with speed 40 m/s at angle theta from horizontal.It is found that projectile is at same height at 1s and 3s.What is the angle of projection?

Discussion

23.	A parallel beam of sodium light of wavelength 6000 ˚A is incident on a thin glass plate of μ=1.5, such that the angle of refraction in the plate is 60∘. The smallest thickness of the plate which will make it appear dark by reflected light is
Answer» A parallel beam of sodium light of wavelength $6000 ˚ A$ is incident on a thin glass plate of $μ = 1.5$ , such that the angle of refraction in the plate is $60^{\circ}$ . The smallest thickness of the plate which will make it appear dark by reflected light is

Discussion

24.	55.The position x of a particle moving along x-axis varies with time as x=4t-2tsquare where x is in metre and t is in second. The rate of change of position with is zero at
Answer» 55.The position x of a particle moving along x-axis varies with time as x=4t-2tsquare where x is in metre and t is in second. The rate of change of position with is zero at

Discussion

25.	A rifle bullet loses 1/20th of its velocity in passing through a plank. What will be the least number of such planks required to just stop the bullet?
Answer» A rifle bullet loses 1/20th of its velocity in passing through a plank. What will be the least number of such planks required to just stop the bullet?

Discussion

26.	In the figure shown, block A is displaced by 0.75 m to the right and block B is displaced by 0.25 m to left. Find the reading of the spring balance. Take g=10 m/s2
Answer» In the figure shown, block $A$ is displaced by $0.75 m$ to the right and block $B$ is displaced by $0.25 m$ to left. Find the reading of the spring balance. Take $g = 10 m / s^{2}$

Discussion

27.	If the mass of the pulleys shown in figure is very very small and the cord is inextensible, the angular frequency of oscillation of the system is
Answer» If the mass of the pulleys shown in figure is very very small and the cord is inextensible, the angular frequency of oscillation of the system is

Discussion

28.	what is pseudo force in non inertial frame
Answer» what is pseudo force in non inertial frame

Discussion

29.	A valley curve has a descending gradient of 1 in 40 followed by an ascending gradient of 1 in 50. The length of the valley curve required for a design speed of 80 km/hour for comfort condition is
Answer» A valley curve has a descending gradient of 1 in 40 followed by an ascending gradient of 1 in 50. The length of the valley curve required for a design speed of 80 km/hour for comfort condition is

Discussion

30.	if a cyclist moving with a speed of 4.9m/s on a level road can take a sharp circular turn of radius 4 m ,then coefficient of friction btw cyclist tyres and road is
Answer» if a cyclist moving with a speed of 4.9m/s on a level road can take a sharp circular turn of radius 4 m ,then coefficient of friction btw cyclist tyres and road is

Discussion

31.	{ 38. A block of mass }1kg is projected from the lowest }}{ point up along the inclined plane. If }g=10ms^{-2} , }} the retardation experienced by the block is
Answer» { 38. A block of mass }1kg is projected from the lowest }}{ point up along the inclined plane. If }g=10ms^{-2} , }} the retardation experienced by the block is

Discussion

32.	What will be the potential of an electric field E= x i + y j ?
Answer» What will be the potential of an electric field E= x i + y j ?

Discussion

33.	A wire of uniform cross section has resistance of 20 ohm . The length of the wire is doubled by stretching and then the elongated wire is cut into four equal parts . The resistance of each part is?
Answer» A wire of uniform cross section has resistance of 20 ohm . The length of the wire is doubled by stretching and then the elongated wire is cut into four equal parts . The resistance of each part is?

Discussion

34.	Ezplain the working of electric motor
Answer» Ezplain the working of electric motor

Discussion

35.	A capacitor of capacitance C carrying a charge Q is connected to an emf source of emf E. Finally, the charge on the capacitor is
Answer» A capacitor of capacitance $C$ carrying a charge $Q$ is connected to an emf source of emf $E$ . Finally, the charge on the capacitor is

Discussion

36.	A truck moving on a smooth horizontal surface with a uniform speed u is carrying stone-dust. If a mass Δm of the stone-dust `leaks down’ from the truck in the time Δt, the force needed to keep the truck moving at its uniform speed is
Answer» A truck moving on a smooth horizontal surface with a uniform speed u is carrying stone-dust. If a mass $Δ m$ of the stone-dust `leaks down’ from the truck in the time $Δ t$ , the force needed to keep the truck moving at its uniform speed is

Discussion

37.	The amount of heat needed to raise the temperature of 4 moles of a rigid diatomic gas from 0∘ C to 50∘ C, when no work is done, is -R is the universal gas constant.
Answer» The amount of heat needed to raise the temperature of $4$ moles of a rigid diatomic gas from $0^{\circ} C$ to $50^{\circ} C$ , when no work is done, is - $R$ is the universal gas constant.

Discussion

38.	An object of height 5 cm is placed at a distance of 30 cm from the convex lens of a focal length 10 cm . The height of image of the object is
Answer» An object of height 5 cm is placed at a distance of 30 cm from the convex lens of a focal length 10 cm . The height of image of the object is

Discussion

39.	Three rods made of same material and having the same cross section have been joined as shown in the ﬁgure. Each rod is of the same length. The left and right ends are kept at 0∘C and 90∘C, respectively. The temperature of the junction of the three rods will be
Answer» Three rods made of same material and having the same cross section have been joined as shown in the ﬁgure. Each rod is of the same length. The left and right ends are kept at $0^{\circ} C$ and $90^{\circ} C$ , respectively. The temperature of the junction of the three rods will be

39.

Three rods made of same material and having the same cross section have been joined as shown in the ﬁgure. Each rod is of the same length. The left and right ends are kept at 0∘C and 90∘C, respectively. The temperature of the junction of the three rods will be

Answer»

Three rods made of same material and having the same cross section have been joined as shown in the ﬁgure. Each rod is of the same length. The left and right ends are kept at $0^{\circ} C$ and $90^{\circ} C$ , respectively. The temperature of the junction of the three rods will be

Discussion

40.	A bus starts from the stop and takes 50 s to attain the speed of 10 ms−1. If the mass of the bus along with the passengers is 10000 kg, calculate the net force acting on the bus to push it to the speed of 10 ms−1.
Answer» A bus starts from the stop and takes $50 s$ to attain the speed of $10 m s^{- 1}$ . If the mass of the bus along with the passengers is $10000 k g$ , calculate the net force acting on the bus to push it to the speed of $10 m s^{- 1}$ .

Discussion

41.	A cylinder of radius is rolling purely on inclined surface the friction is acting up or down
Answer» A cylinder of radius is rolling purely on inclined surface the friction is acting up or down

Discussion

42.	If a body looses half of its velocity on penetrating 3 cm in a wooden block, then how much will it penetrate more before coming to rest?
Answer» If a body looses half of its velocity on penetrating $3 cm$ in a wooden block, then how much will it penetrate more before coming to rest?

Discussion

43.	The position }x of a particle moving along }x -axis at }{ time }(t) is given by the equation }t=\sqrt x+2 , where }}x is metres and }t in seconds. Find the work } done by the force in first four seconds. } (1) Zero } (2) }2J (3) }4J (4) }8J
Answer» The position }x of a particle moving along }x -axis at }{ time }(t) is given by the equation }t=\sqrt x+2 , where }}x is metres and }t in seconds. Find the work } done by the force in first four seconds. } (1) Zero } (2) }2J (3) }4J (4) }8J

Discussion

44.	What is the reason for a sound produced when we write with a chalk on the black board?
Answer» What is the reason for a sound produced when we write with a chalk on the black board?

Discussion

45.	One end of a massless spring of spring constant k=200 N/m and natural length 0.5 m is fixed at the centre of a frictionless horizontal table. The other end is connected to a load of mass 1 kg lying on the table at rest. If the spring remains horizontal and mass is made to rotate at an angular speed of 2 rad/s, find the elongation in the spring.
Answer» One end of a massless spring of spring constant $k = 200 N/m$ and natural length $0.5 m$ is fixed at the centre of a frictionless horizontal table. The other end is connected to a load of mass $1 kg$ lying on the table at rest. If the spring remains horizontal and mass is made to rotate at an angular speed of $2 rad/s$ , find the elongation in the spring.

Discussion

46.	Two tuning forks with natural frequencies 340 Hz each move relative to stationary observer. One fork moves away from the observer while the other moves towards him at the same speed. The observer hears beats of frequency 3 Hz. Find the speed of the tuning fork (velocity of sound in air is 340 m/s).
Answer» Two tuning forks with natural frequencies $340 Hz$ each move relative to stationary observer. One fork moves away from the observer while the other moves towards him at the same speed. The observer hears beats of frequency $3 Hz$ . Find the speed of the tuning fork (velocity of sound in air is $340 m/s$ ).

Discussion

47.	Emw of intensity I falling normally on a perfectly reflecting surface. The pressure exerted by wave on the surface is
Answer» Emw of intensity I falling normally on a perfectly reflecting surface. The pressure exerted by wave on the surface is

Discussion

48.	In an LR circuit, the value of L is 0.4π H and the value R is 30 Ω. If in the circuit, an alternating emf of 200 V rms value at 50 cycles/s is connected, the peak current of the circuit is k√2 A .The value of k is (integer only)
Answer» In an $L R$ circuit, the value of $L$ is $\frac{0.4}{π} H$ and the value $R$ is $30 Ω$ . If in the circuit, an alternating $e m f$ of $200 V$ $r m s$ value at $50 cycles/s$ is connected, the peak current of the circuit is $k \sqrt{2} A$ .The value of $k$ is (integer only)

Discussion

49.	Find electric field at a point (5,-3,6)due to a point charge -2c placed at (-1,4,-2)?
Answer» Find electric field at a point (5,-3,6)due to a point charge -2c placed at (-1,4,-2)?

Discussion

50.	Wavelength of photon having energy 2.5 eV:(Take Planck's constant, h=6.6×10−34 Js)
Answer» Wavelength of photon having energy $2.5 eV$ : $(Take Planck's constant, h = 6.6 \times 10^{- 34} Js)$

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The value of ∫dx1+3cos2x(where C is integration constant)

Three particles, each of mass m, are placed at the corners of a right-angled triangle as shown in the figure. If OA = a and OB = b, the position vector of the centre of mass is

particle A makes a perfectly elastic collision with another particle B at rest. they fly apart in opposite direction with equal speeds. If their masses are mA and mB respectively, then (a)2ma=mB (b)3mA=mB (c)4mA=mB (d)\surd3mA= m

Give the expansions of PSLV and GSLV.

The diagram shows a cyclic process performed on one mole of an ideal gas. A total of 1000 J of heat is withdrawn from the gas in a complete cycle. Find the work done by the gas in the process B→C

Electric field close to plane of charge is shown in figure. External electric field in V/m is

In a wire of cross-section radius r, free electrons travel with drift velocity vd, when a current I flows through the wire. What is the current in another wire of half the radius and of the same material, when the drift velocity is 2vd ?

20.Calculate the acceleration of the masses 12kg shown in figure. Also calculate the tension in the string connecting the 12kg mass the string are massless and unextensible. Pulleys are massless and frictionless

What should be the value of the refractive index n of a glass rod placed in air so that the light entering through flat surface of the rod does not cross the curved surface of the rod?

11. if there are 3 electrons present in each orbital and bohr -burry principal is not followed in filling of electrons the number of elements in 4th period of modern periodic table will be:

A pair of spur gears with module 5 mm and a center distance of 450 mm is used for a speed reduction of 5 : 1. The number of teeth on pinion is

A car of mass 1000 kg moves on a circular track of radius 20 m, if the coefficient of friction is 0.64 then the maximum velocity with which the car can move is

A policeman moving on a highway with a speed of 30 kmh−1 fires a bullet at a thief's car speeding away in the same direction with a speed of 192 kmh−1. If the muzzle speed of the bullet is 150 ms−1 with what speed does the bullet hit the thief's car?

78. With increase in frequency of an AC supply, the impedance of an LCR circuit a) remain constant b) increases c) decreases d) decrease at first, becomes minimum and then increases

A particle travels along the arc of a circle of radius r.Its speed depends on the distance travelled L as v=aL,where 'a'is a constant. The angle a between the vectors of total acceleration and the velocity of the particle is

A projectile is thrown with speed 40 m/s at angle theta from horizontal.It is found that projectile is at same height at 1s and 3s.What is the angle of projection?

A parallel beam of sodium light of wavelength 6000 ˚A is incident on a thin glass plate of μ=1.5, such that the angle of refraction in the plate is 60∘. The smallest thickness of the plate which will make it appear dark by reflected light is

55.The position x of a particle moving along x-axis varies with time as x=4t-2tsquare where x is in metre and t is in second. The rate of change of position with is zero at

A rifle bullet loses 1/20th of its velocity in passing through a plank. What will be the least number of such planks required to just stop the bullet?

In the figure shown, block A is displaced by 0.75 m to the right and block B is displaced by 0.25 m to left. Find the reading of the spring balance. Take g=10 m/s2

If the mass of the pulleys shown in figure is very very small and the cord is inextensible, the angular frequency of oscillation of the system is

what is pseudo force in non inertial frame

A valley curve has a descending gradient of 1 in 40 followed by an ascending gradient of 1 in 50. The length of the valley curve required for a design speed of 80 km/hour for comfort condition is

if a cyclist moving with a speed of 4.9m/s on a level road can take a sharp circular turn of radius 4 m ,then coefficient of friction btw cyclist tyres and road is

{ 38. A block of mass }1kg is projected from the lowest }}{ point up along the inclined plane. If }g=10ms^{-2} , }} the retardation experienced by the block is

What will be the potential of an electric field E= x i + y j ?

A wire of uniform cross section has resistance of 20 ohm . The length of the wire is doubled by stretching and then the elongated wire is cut into four equal parts . The resistance of each part is?

Ezplain the working of electric motor

A capacitor of capacitance C carrying a charge Q is connected to an emf source of emf E. Finally, the charge on the capacitor is

A truck moving on a smooth horizontal surface with a uniform speed u is carrying stone-dust. If a mass Δm of the stone-dust `leaks down’ from the truck in the time Δt, the force needed to keep the truck moving at its uniform speed is

The amount of heat needed to raise the temperature of 4 moles of a rigid diatomic gas from 0∘ C to 50∘ C, when no work is done, is -R is the universal gas constant.

An object of height 5 cm is placed at a distance of 30 cm from the convex lens of a focal length 10 cm . The height of image of the object is

Three rods made of same material and having the same cross section have been joined as shown in the ﬁgure. Each rod is of the same length. The left and right ends are kept at 0∘C and 90∘C, respectively. The temperature of the junction of the three rods will be

A bus starts from the stop and takes 50 s to attain the speed of 10 ms−1. If the mass of the bus along with the passengers is 10000 kg, calculate the net force acting on the bus to push it to the speed of 10 ms−1.

A cylinder of radius is rolling purely on inclined surface the friction is acting up or down

If a body looses half of its velocity on penetrating 3 cm in a wooden block, then how much will it penetrate more before coming to rest?

The position }x of a particle moving along }x -axis at }{ time }(t) is given by the equation }t=\sqrt x+2 , where }}x is metres and }t in seconds. Find the work } done by the force in first four seconds. } (1) Zero } (2) }2J (3) }4J (4) }8J

What is the reason for a sound produced when we write with a chalk on the black board?

Two tuning forks with natural frequencies 340 Hz each move relative to stationary observer. One fork moves away from the observer while the other moves towards him at the same speed. The observer hears beats of frequency 3 Hz. Find the speed of the tuning fork (velocity of sound in air is 340 m/s).

Emw of intensity I falling normally on a perfectly reflecting surface. The pressure exerted by wave on the surface is

In an LR circuit, the value of L is 0.4π H and the value R is 30 Ω. If in the circuit, an alternating emf of 200 V rms value at 50 cycles/s is connected, the peak current of the circuit is k√2 A .The value of k is (integer only)​​​

Find electric field at a point (5,-3,6)due to a point charge -2c placed at (-1,4,-2)?

Wavelength of photon having energy 2.5 eV:(Take Planck's constant, h=6.6×10−34 Js)

In an LR circuit, the value of L is 0.4π H and the value R is 30 Ω. If in the circuit, an alternating emf of 200 V rms value at 50 cycles/s is connected, the peak current of the circuit is k√2 A .The value of k is (integer only)